The crypts at the church were forced to close temporarily after they were vandalised on the weekend of February 23rd-25th.

The break-in was noted when a guide was preparing to open St Michan’s for visitors. The guide discovered the head of ‘the Crusader’ had been severed from its mummified body and was missing.

The head of a mummified nun, who died 300 years ago, had also been turned 180 degrees to face the wrong direction while a third mummy had been turned on its side.

The crypt of the family of Irish mathematician William Hamilton was also damaged.

The Garda said in a statement that members of the force from the Bridewell station had recovered the head of ‘the Crusader’ as well as another skull that had been taken from the crypt.

The items were recovered as a result of information that came into the possession of the investigating gardaí. The force said the National Museum of Ireland was acting in an advisory capacity.

“An Garda Síochána would like to thank the public for their assistance in the investigation, which remains ongoing,” added the statement.

The vaults receive about 28,000 visitors a year. The Archdeacon of Dublin, the Ven David Pierpoint warned that the closure of the crypts would significantly affect the revenue used to maintain St Michan’s, which was founded in 1095.